1. Field
One embodiment of the invention relates to a flexible printed wiring board and an electronic apparatus having the flexible printed wiring board.
2. Description of the Related Art
Flexible printed wiring boards are often used for connecting movable parts of peripheral devices of computers, such as hard disk drives (HDDs) and an optical disc drives (ODDs), owing to their high flexibility.
Flexible printed wiring boards are arranged in computer devices in a bent manner. Therefore, when there is a friction between portions of a flexible printed wiring board, particles may be scraped off from a film surface of the outermost layer of the flexible printed wiring board or a wiring disconnection may be caused. In view of this, for example, JP-A-2007-194341 describes a technique in which a textured structure is formed on the outermost layer of a flexible printed wiring board to improve abrasion resistance, thereby preventing scraping of particles and wiring disconnection.
Due to its high flexibility, a portion of the flexible printed wiring board, where a component such as a connector is to be mounted, needs to be reinforced in order to ensure strength required for the mounting. Generally, such a partial reinforcement is implemented by using an adhesive to firmly bond an inflexible reinforcing sheet onto a back side of the mounting area of the flexible printed wiring board.
However, the flexible printed wiring board is made of highly hygroscopic material. Therefore, during a heating treatment for hardening the adhesive, which is applied on the connector mounting area of the flexible printed wiring board to bond the reinforcing sheet thereon, water vapor is generated between the adhesive and the flexible printed wiring board. The water vapor may cause a reduction in adhesion strength between the flexible printed wiring board and the adhesive, which would result in insufficient reinforcement. Insufficient adhesion between the reinforcing sheet and the flexible printed wiring board may cause a connection error between the flexible printed wiring board and a component to be mounted thereon.